A crowd of some 150,000 people, largely white, gathered at Whitehall in central London carrying a tide of banners. The tension is clearest around hotels where the government is housing asylum-seekers, which have become chronic flashpoints for flag-waving protests. So, crossing via small boats has become the only available means to enter into the British asylum process. The hotel housing asylum-seekers in the village of Stanwell, near Heathrow Airport, has become a point of friction. Mr. Katwala says the controversy over asylum hotels is because of the powerful symbolism.